Primer composition and curable composition

ABSTRACT

A curable composition comprising a polymerizable monomer having an acidic group in its molecule and an initiator. The composition has a viscosity in the range of from 100 to 30,000 cP at 37.5° C. and may have additionally contain other polymerizable monomer and/or a filler. The composition is applied to a tooth surface directly or after applying a primer composition. There is also provided the primer composition which comprises a polymerizable monomer having an acidic group and a solvent.

This is a division of application Ser. No. 08/284,175 filed Aug. 2,1994, now U.S. Pat. No. 5,530,038.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a primer composition with which a toothcan be surface-treated by facile handling, and a curable compositionwhich can be bonded to a tooth. More specifically, it relates to aprimer composition and a curable composition which are advantageouslyused for restoring a tooth-surface coating material or restoring dentalrestorative resins such as a PMMA resin, resin cement and a compositeresin.

An adhesive material for a tooth is desired not only to bond a tooth anda restorative material tightly and firmly but also to permit thecompletion of the restoration as easily and shortly as possible, sincethe restoration is conducted in the mouth.

For bonding a resin restorative material to a tooth firmly, there isemployed one of the following three tooth-surface treating methods. Thatis, the first one of these methods is a total etching method in whichenamel and dentin are first decalcified by simultaneously applyingphosphoric acid or citric acid aqueous solution to surfaces of theenamel and dentin, total washed with water and dried. The second one isa total etching--dentin primer method in which a primer is applied to adentin surface treated by the total etching method and then dried. Thethird one is an enamel etching--dentin primer method in which an enamelalone is etched and a primer is applied to remaining dentin.

The first total etching method is carried out through the steps ofapplying an etching agent, washing with water and drying, while it iseffective as a bonding method since it is not a time-consuming method.Since, however, dental tubules are widely opened, a patient may havestrong pains when an adhesive material is applied thereafter. Further,the bonding strength to dentin is lower than the bonding strength toenamel in many cases, and the interface between dentin and the adhesivematerial has a gap, which induces secondary caries or pulpits. Thesecond method is an improvement of the first method. In which, further,a primer is applied to dentin and dried. The first method is therebyimproved to some extent. However, the second method requires anadditional bonding procedure, which not only causes more pains on apatient but requires an additional time for the treatment. The thirdmethod is for decreasing pains to be caused on a patient, In whichenamel alone is etched so that dental tubules are not opened, and aprimer is applied. The purpose in this method is nearly accomplished,while the following problems still remain to be solved. That is, it isrequired to apply an etching agent only to a small and complicatedenamel portion of a cavity where it is difficult to apply the etchingagent distinctly, and the treatment takes time. That is because there isno primer which can treat both enamel and dentin and has high bondingstrength.

On the other hand, for bonding a restorative material to a toothstrongly, it is considered essential to infiltrate an adhesive materialinto a tooth tissue sufficiently and cure it firmly. For sufficientlydiffusing an adhesive material component into a tooth, a variety ofdiffusion-promoting monomers have been proposed, and dental adhesivecompositions containing these monomers have been proposed. For thefacile infiltration of an adhesive material, there have been proposed amethod of etching and primer compositions for the surface treatment of atooth. In general practice, these adhesive materials and primercompositions are arranged to have relatively low viscosities for thefacile infiltration into a tooth tissue.

Further as a material with which an adhesive interface is filled withoutforming any gap, JP-A-63-162705 discloses a filler having a highviscosity as compared with an adhesive material (called a low-viscosityfiller or a low-viscosity resin). The low-viscosity filler has a highviscosity and sticking nature, and it is therefore effective forimproving the full contact in the adhesion interface, while the degreeof filtration thereof into a tooth is low so that its adhesion to thetooth is poor. It is therefore used in combination with a primer or anadhesive material.

In prior art practice, the following has been considered the mostpreferred technique for bonding a restorative material to a tooth firmlywithout forming any gap. That is, a tooth surface is treated by etchingand/or with a primer, an adhesive material is applied to the toothsurface and cured, the tooth surface is coated with a low-viscosityfiller and then a restorative filler such as a composite resin is filledin. However, the dental treatment therefor takes a very long period oftime so that a patient is forced to suffer much pains, and it is also atime-consuming treatment on a dentist's part. It therefore cannot besaid that the above practice is preferable.

For adhesion performance, many adhesive materials and bonding methodshave been proposed and improved. Experimental adhesion performances inthese proposals are excellent, while these proposals are notsatisfactory since no sufficient performances are exhibited when theyare actually clinically evaluated. It is assumed that the aboveunsatisfactory performances can be explained on the basis of adifference between an adhesion surface used in an experiment foradhesion performance and an actual adhesion surface in the mouth. It ispointed out, in particular, that a dry state differs between the aboveadhesion surfaces.

The prior art practice therefore has the following serious problems. Adentist and a patient are forced to have efforts or suffer much painsfor a long period of time for bonding a restorative material to a toothfirmly without forming any gap, and further, an adhesive material cannotexhibit adequate adhesion performance in the mouth where a sufficientdry state cannot be maintained.

It is therefore an object of the present invention to provide a primercomposition or a tooth surface treating agent with which a tooth can besurface-treated by facile handling.

It is another object of the present invention to provide a primercomposition with which enamel and dentin can be surface-treated at thesame time and procedures such as washing with water are not required, sothat the time required for the treatment by a dentist can be decreasedand that pains caused on a patient can be alleviated.

It is further another object of the present invention to provide acurable composition which can be bonded to a tooth, dentin inparticular, by facile handling and without forming any gap even underwet conditions.

It is still further another object of the present invention to provide acurable composition which has adhesion properties to dentin not treatedwith acid etching or a primer and has a high viscosity and stickingnature as an adhesive so that, advantageously, no gap is formed in anadhesion interface, and while therefore can be bonded to dentin byfacile handling.

Other objects and advantages of the present invention will be apparentfrom the following description.

The above objects and advantages of the present invention will beachieved by the primer composition and the curable composition of thepresent invention which will be detailed hereinafter.

First, the curable composition will be detailed below.

The curable composition of the present invention comprises

(A1) (a) a polymerizable monomer having an acidic group in its molecule,

(b) a polymerizable monomer having a hydroxyl group in its molecule, and

(c) a polymerization initiator,

wherein:

on the basis of a total amount of components (a), (b) and (e), theamount of the component (a) is 1 to 50% by weight, the amount of thecomponent (b) is 1 to 98.99% by weight and the amount of the component(c) is 0.01 to 50% by weight,

(B1) the curable composition having a viscosity in the range of from 100to 30,000 cp when measured at 37.5° C.

The curable composition of the present invention has all of wettabilityto a tooth surface, reactivity to a tooth and infiltration properties toa tooth at the same time and can be bonded to a living hard tissuewithout forming any gap by facile handling.

When the curable composition of the present invention is applied to atooth, dentin in particular, it, is preferred to bring it into contactwith a wet tooth in view of safety to dental pulp. In some use, a toothmay be surface-treated with an etching agent such as a phosphoric acidaqueous solution while may contain a metal salt, a citric acid aqueoussolution or EDTA aqueous before solution the curable composition of thepresent invention is applied.

The (a) polymerizable monomer having an acidic group in its molecule,used in the curable composition of the present invention, has apolymerizable group selected from radical-polymerizable unsaturatedgroups such as a (meth)acryloyl group, a styryl group, a vinyl group andan allyl group. The polymerizable monomer (a) is a monomer of which themolecule contains at least one member selected from the abovepolymerizable groups (a polymerizable group in polymcrizable monomers tobe described hereinafter should be all interpreted in this sense).

In the curable composition of the present invention, the component (a)is a polymerizable monomer containing an acidic group in its molecule.The acidic group in the above polymerizable monomer includes acarboxylic acid group, a phosphoric acid group, a thiophosphoric acidgroup, a sulfonic acid group and a sulfinic acid group. The component(a) preferably contains at least one of the above acidic groups.

Of the polymerizable monomers used as the component (a) , thepolymerizable monomer having at least one carboxyl group in its moleculeincludes monocarboxylic acid, dicarboxylic acid, tricarboxylic acidtetracarboxylic acid and derivatives of these such as (meth)acrylicacid, maleic acid, p-vinylbenzoic acid,11-(meth)acryloyloxy-1,1-undecanedicarboxylic acid (where it ismethacrylate: MAC-10), 1,4-di(meth)acryloyloxyethylpyromellitic acid,6-(meth)acryloyloxyethylnaphthalene-1,2,6 -tricarboxylic acid,4-(meth)acryloyloxymethyltrimelltic acid and an anhydride thereof,4-(meth)acryloyloxyethyltrimellitic acid (where it is methacrylate:4-MET) and an anhydride thereof (where it is methacrylate: 4-META),4-(meth)acryloyloxybutyltrimellitic acid and an anhydride thereof,4-[2-hydroxy-3-(meth)acryloyloxy]butyltrimellitic acid and an arthydridethereof, 2,3-bis(3,4-dicarboxybenzoyloxy)propyl (meth)acrylate,N,O-di(meth)acryloyloxytyroslne, O-(meth)acryloyloxytyrosine,N-(meth)acryloyloxytyrosine, N-(meth)acryloyloxyphenylalanine,N-(meth)acryloyl-p-aminobenzoic acid, N-(meth)acryloyl-O-aminobenzoicacid, N-(meth)acryloyl-5-aminosalicytic acid (where it is methacrylate:5-MASA), N-(meth)acryloyl-4-aminosalicylic acid, 2-, 3- or4-(meth)acryloyloxybenzoic acid, an adduct of 2-hydroxyethyl(meth)acrylate with pyromellitic dianhydride (where it is methacrylate:PMDM), an addition reaction product of 2-hydroxyethyl (meth)acrylatewith maleic anhydride or 3,3', 4,4'-benzophenonetetracarboxylicdianhydride (where it is methacrylate: BTDA) or 3,3',4,4'-biphenyltetracarboxylic dianhydride, an adduct of2-(3,4-dicarboxybenzoyloxy) 1,3-di(meth)acryloyloxypropane,N-phenylglycine or N-tolylglyclne with glycidyl (meth)acrylate,4-((2-hydroxy-3-(meth)acryloyloxypropyl)amino)phthalic acid, and 3- or4-(N-methyl-N(2-hydroxy-3-(meth) acryloyloxypropyl)amino)phthalic acid.Preferred are MAC-10, 4-MET and 5-MASA. The above polymerizable monomershaving a carboxyl group may be used alone or in combination.

Of the polymerizable monomers used as the component (a), thepolymerizable monomer having at least one phosphoric acid group in itsmolecule includes 2-(meth)acryloyloxyethyl acidophosphate, 2- and3-(meth)acryloyloxypropyl acidophosphate, 4-(meth)acryloyloxybutylacidophosphate, 6-(meth)acryloyloxyhexyl acidophosphate,8-(meth)acryloyloxyoctyl acidophosphate, 10-(meth)acryloyloxydecylacidophosphate, 12-(meth)acryloyloxydodecyl acidophosphate,bis{2-(meth)acryloyloxyethyl}acidophosphate, bis{2- or3-(meth)acryloyloxypropyl}acidophosphate, 2-(meth)acryloyloxyethylphenylacidophosphate, and 2-(meth)acryloyloxyethyl p-methoxyphenylacidophosphate. The phosphoric acid group in these compounds may bereplaced with a thiophosphoric acid group. Preferred are2-(meth)acryloyloxyethylphenyl acidophosphate and10-(meth)acryloyloxydecyl acidophosphate. The above polymerizablemonomers having a phosphoric acid group may be used alone or incombination.

Of the polymerizable monomers used as the component (a), thepolymerizable monomer having at least one sulfonic acid group in itsmolecule includes 2-sulfoethyl (meth)acrylate, 2- or 1-sulfo-1 or2-propyl (meth)acrylate, 1- or 3-sulfo-2-butyl (meth)acrylate,3-bromo-2-sulfo-2-propyl (meth)acrylate, 3-methoxy-1-sulfo-2-propyl(meth)acrylate, and 1,1-dimethyl-2-sulfoethyl (meth)acrylamide.Preferred is 1,1-dimethyl-2-sulfoethyl (meth)acrylamide. The abovepolymerizable monomers having a sulfonic acid may be used alone or incombination.

All the above polymerizable monomers included in the component (a) maybe used alone or in combination.

In the curable composition of the present invention, the component (b)is a polymerizable monomer containing hydroxyl group in its molecule.Further, this polymerizable monomer containing a hydroxyl group mayfurther contain any one of functional groups such as a carboxyl group, aphosphoric acid group, a sulfonic acid group, a hydroxyl group, an aminogroup and a glycidyl group.

Of the polymerizable monomers used as the component (b), thepolymerizable monomer having (meth)acryloyl group includes hydroxylgroup-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate,2- or 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate,5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate,10-hydroxydecyl (meth)acrylate, 1,2- or 1,3- and 2,3-dihydroxypropane(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycolmono(meth)acrylate, pentaethylene glycol mono(meth)acrylate,polyethylene glycol mono(meth)acrylate and dipropylene glycolmono(meth)acrylate; hydroxyl group-containing (meth)acrylamides such asmethylol (meth)acrylamide, N-(meth)acryloyl-2,3-dihydroxypropylamine andN-(meth)acryloyl-1,3-dihydroxypropylamine; and adducts of glycidylmethacrylate with aliphatic or aromatic polyols (including phenol) suchas 2-hydroxy-3-phenoxypropyl (meth)acrylate (where it is methacrylate:HPPM), 2-hydroxy-3-naphthoxypropyl (meth)acrylate (where it ismethacrylate: HNPM) and an addition reaction product of 1 mol ofbisphenol A with 2 mol of glycidyl (meth)acrylate (where it ismethacrylate: GMA) (where the addition reaction product is methacrylate:Bis-GMA). The above polymcrizable monomers may be used alone or incombination.

Of the above polymerizable monomers as the component (b), it isparticularly preferred to use monomers whose solubility in water is atleast 0.5 g/100 cc. It is assumed that this monomer plays the role ofallowing the curable composition to easily infiltrate a tooth tissueeven when the curable composition is applied to an adhesion interfacehaving a high water content. The solubility used in the presentinvention is defined as follows. That is, 0.5 part by weight of amonofunctional (meth)acrylate monomer having at least one hydroxyl groupin its molecule is added to 100 parts by weight of water having atemperature of 25° C. and the mixture is shaken for 10 minutes. Then,the mixture is allowed to stand at 25° C. for 10 minutes and thenvisually evaluated. When the mixture solution has separated phases or isa turbid solution, the solubility of the above (meth)acrylate in wateris taken as less than 0.5 g/100 cc. When the mixture is a transparentsolution, the solubility is taken as at least 0.5 g/100 cc.

The component (b) whose solubility in water is at least 0.5 g/100 ccincludes 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl(meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl(meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycolmono(meth)acrylate, tetraethylene glycol mono(meth)acrylate,polyethylene glycol mono(meth)acrylate, dipropylene glycolmono(meth)acrylate, tripropylene glycol mono(meth)acrylate,tetrapropylene glycol mono(meth)acrylate, polypropylene glycolmono(meth)acrylate, 1,3- or 2,3-dihydroxypropyl (meth)acrylate,N-(meth)acryloyl-2,3-dihydroxylpropylamine andN-(meth)acryloyl-3-dihydroxypropylamine. These monomers may be usedalone or in combination. Of these polymerizable monomers, 2-hydroxyethyl(meth)acrylate (where it is methacrylate: HEMA) is particularlypreferred, and it is preferred to incorporate 40 to 98.99 parts byweight, per 100 parts by weight of the total amount of the components(a), (b) and (c), of 2-hydroxyethyl (meth)acrylate as part of thecomponent (b).

In the curable composition of the present invention, the component (c)is a polymerization initiator. This polymerization initiator includesorganic peroxide, inorganic peroxide, alkylborane, partially oxidizedalkylborane, an α-diketone compound, an organic amine compound, organicsulfinic acid, organic sulfonic acid salt, an inorganic sulfur compoundand barbituric acids. The above polymerization initiators may be usedalone or in combination. The above polymerization initiators can begrouped into a type for room temperature chemical polymerization, a typefor photopolymerization and a dual type for a combination of the abovepolymerizations. The peroxide (polymerization initiator) which is usedas a type for room temperature chemical polymerization includes organicperoxides such as diacetyl peroxide, dipropyl peroxide, dibutylperoxide, dicapryl peroxide, dilauryl peroxide, benzoyl peroxide (BPO),p,p'-dichlorobenzoyl peroxide, p,p'-dimethoxybenzoyl peroxide,p,p'-dimethylbenzoyl peroxide and p,p'-dinitrobenzoyl peroxide andinorganic peroxides such as ammonium persulfate, potassium persulfate,potassium chlorate, potassium bromate and potassium perphosphate. Ofthese, BPO is preferred.

The polymerization initiator which is used as a type for thephotopolymerization is a polymerization initiator with which thepolymerization can be carried out by irradiating the composition withultraviolet light or visible light. The polymerization initiator usedfor the above photopolymerization is not specially limited. The abovepolymerization initiator includes ultraviolet light or visible lightsensitizers such as α-diketone compounds including benzil,4,4'-dichlorobenzil, benzoin, benzoin methyl ether, benzoin ethyl ether,benzoin isopropyl ether, benzophenone, 9,10-anthraquinone, diacetyl andd,l-camphorquinone (CQ).

When the polymerization is carried out in the presence of apolymerization initiator which is a type for room temperature chemicalpolymerization or photopolymerization, a reducing compound may be usedin combination. The organic reducing compound includes aromatic aminessuch as N,N-dimethylaniline, N,N-dimethyl p-toluidine (DMPT),N,N-diethyl p-toluidine, N,N-diethanol p-toluidine (DEPT), N,N-dimethylp-tertbutylaniline, N,N-dimethylanisidine, N,N-dimethyl pchloroaniline,N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl(meth)acrylate, N,N-dimethylaminobenzoic acid and alkyl ester thereof,N,N-diethylaminobenzoic acid (DEABA) and alkyl ester thereof andN,N-dimethylaminobenzaldehyde (DMABAd); N-phenylglycine (NPG),N-tolylglycine (NTG) andN,N-(3-methacryloyloxy-2-hydroxypropyl)phenylglycine (NPG-GMA).

Of the above reducing compounds, preferred are DMPT, DEPT, DEABA,DMABAd, NPG and NTG.

Further, for reliably curing the curable composition of the presentinvention and improving the curable composition of the present inventionin adhesion to a tooth, it is preferred to incorporate at least one ofamine compounds of the formula (I), ##STR1## wherein each of R¹ and R²is independently a hydrogen atom or an alkyl group which may contain afunctional group or a substituent, and R³ is a hydrogen atom or metal,and of the formula (II), ##STR2## wherein each of R⁴ and R⁵ isindependently a hydrogen atom or an alkyl group, and R⁶ is a hydrogenatom, an alkyl group which may contain a functional group or asubstituent or an alkoxyl group which may contain a functional group ora substituent.

The amine compound coming under the formula (I) includes NPG, NTG andNPG-GMA which are already described. NPG is particularly preferred. Theamine compound of the formula (II) includes, in addition toN,N-dimethylaminobenzoic acid and alkyl ester thereof andN,N-diethylaminobenzoic acid (DEABA) and alkyl ester thereof, which arealready described, aliphatic alkylaminobenzoic acids and alkyl estersthereof typified by N,N-dipropylaminobenzoic acid and alkyl esterthereof, N-isopropylaminobenzoic acid and alkyl ester thereof andN-isopropyl-N-methylaminobenzoic acid and alkyl ester thereof; aliphaticalkylaminobenzoaldehydes typified by DMABAd,N,N-diethylaminobenzoaldehyde, N,N-dipropylaminobenzoaldehyde andN-isopropyl-N-methylaminobenzaldehyde; aliphaticalkylaminoacetylbenzenes typified by N,N-dimethylaminoacetylbenzene,N,N-diprohylaminoacetylbenzene, N,N-dipropylaminoacetylbenzene,N-isopropylaminoacetylbenzene and N-isopropyl-N-methylaminoacetylbenzeneand aliphatic alkylaminoacylbenzenes. These amine compounds may be usedalone or in combination.

In addition to the above compounds, the reducing compound includesaromatic sulfinic acids such as benzenesulfinic acid, o-toluenesulfinicacid, ethylbenzenesulfinic acid, decylbenzenesulfinic acid,dodecylbenzenesulfinic acid, chlorobenzenesulfinic acid andnaphthalenesulfinic acid and salts thereof.

The inorganic reducing compound is preferably selected fromsulfur-containing, reducing inorganic compounds. These compounds arepreferably reducing inorganic compounds used as redox initiators whichcan be used for polymerizing a radical-polymerizable monomer in asolvent such as water of a water-containing solvent. Examples thereofinclude sulfurous acid, bisulfurous acid, metasulfurous acid,metabisulfurous acid, pyrosulfurous acid, thiosulfurous acid, dithionousacid, dithtonie acid, hyposulfurous acid, hydrosulfurous acid and saltsof these. Of these, sulfites are preferred, and particularly preferredare sodium sulfite, potassium sulfite, sodium hydrogensulfite andpotassium hydrogensulfite. These reducing inorganic compounds may beused alone or in combination.

Per 100 parts by weight of the components (a), (b) and (c), the curablecomposition of the present invention contains 1 to 50 parts by weight ofthe component (a) , 1 to 98.99 parts by weight of the component (b) and0.01 to 50 parts by weight of the component (c). Preferably, the curablecomposition contains 1 to 30 parts by weight of the component (a), 3 to90 parts by weight of the component (b) and 0.1 to 20 parts by weight ofthe component (c).

The curable composition of the present invention may further contain atleast one of

(d) other polymerizable monomer copolymerizable with at least one of theabove components (a) and (b), and

(e) at least one member selected from the group consisting of an organicfiller, an inorganic filler and an organic composite filler.

The curable composition of the present invention, which contains none ofthe above components (d) and (e), will be referred to as a first curablecomposition. The curable composition of the present invention, whichcontains the component (d) alone, will be referred to as a secondcurable composition. The component (d) is a polymerizable monomer whichis copolymerizable with at least one of the components (a) and (b). Thispolymerizable monomer includes monomers having radical-polymerizableunsaturated group such as a (meth)acryloyl group, a styryl group, avinyl group or an allyl group. The polymerizable monomer can be amonomer whose molecule has at least one group selected from the abovepolymerizable groups. The above polymerizable monomer may contain, inits molecule, a functional group such as a carboxyl group, a phosphoricacid group, a sulfonic acid group, a hydroxyl group, an amino group or aglycidyl group.

The polymerizable monomer used as the component (d) includes aliphaticesters of (meth)acrylate acids such as methyl (meth)acrylate, ethyl(meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, neopentylglycol di(meth)acrylate and trimorbylolpropane tri(meth)acrylate;polyethylene glycol di(meth)acrylates such as ethylene glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycoldi(meth)acrylate, pentaethylene glycol di(meth)acrylate, nonaethyleneglycol di(meth)acrylate and tetradecaethylene glycol di(meth)acrylate;polypropylene glycol di(meth)acrylates such as propylene glycoldi(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropyleneglycol di(meth)acrylate and nonapropylene glycol di(meth)acrylate;mono(meth)acrylates in which the (meth)acryloyl group of the abovepolyethylene glycol di(meth)acrylates or the above polypropylene glycoldi(meth)acrylates is replaced with a methyl group or an ethyl group;(meth)acrylates having a urethane bond such as an adduct of2-(meth)acryloyloxyethyl isocyanate, 2,2,4-trimethylhexamethylenediisocyanate or 1,3,5-trimethylhexamethylene diisocyanate with2-hydroxyethyl (meth)acrylate;2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propanes obtained by formingan adduct of bisphenol A with oxyethylene and further condensing theadduct and (meth)acrylic acid; styrene derivatives such as styrene,4-methylstyrene, 4-chloromethylstyrene and divinylbenzene; and vinylacetate. These polymerizable monomers may be used alone or incombination.

The above various polymerizable monomers described as the component (d)may be used alone or in combination.

On the basis of the total amount of the components (a), (b) and (c), thesecond curable composition of the present invention contains 1 to 50% byweight of the component (a), 1 to 98.99% by weight of the component (b)and 0.01 to 50% by weight of the component (c). Further the secondcurable composition of the present invention contains the component (d)in an amount of 3 to 50% by weight on the basis of the total amount ofthe components (a), (b), (e) and (d).

The first and second curable compositions of the present invention arerequired to have a viscosity in the range of from 100 to 30,000 cP,preferably 100 to 20,000 cP, more preferably 100 to 8,000 cP, whenmeasured at 37.5° C. with a viscometer TYPE-EHD (supplied by TOKIMECCo., Ltd). Having the viscosity in the above range, the first and secondcurable compositions exhibit excellent full contact and adhesionproperties without forming any gap in an adhesion interface with atooth.

The curable composition of the present invention which further, containsthe component (e) alone, will be referred to as a third curablecomposition.

In the third curable composition of the present invention the component(e) is at least one filler selected from an organic filler, an inorganicfiller and an organic composite filler. The organic filler includes apowdered polymer filler obtained by milling a polymer or by dispersionpolymerization, and a filler obtained by polymerizing a polymerizablemonomer containing a crosslinking agent and milling the resultantpolymer. The polymerizable monomer as a raw material for the abovefiller is not specially limited, while a polymer is preferably selectedfrom homopolymers and copolymers from those polymerizable monomersdescribed with regard to the components (b) and (d). The polymerincludes polymethyl methacrylate (PMMA) , polyethyl methacrylate,polypropyl methacrylate polybutyl methaerylate (PBMA), polyvinyl acetate(PBAc), polyethylene glycol (PEG), polypropylene glycol (PPG) andpolyvinyl alcohol (PVA).

The inorganic filler includes silica, silica alumina, alumina, aluminaquartz, glass (including barium glass), titania, zirconia, calciumcarbonate, kaolin, clay, mica, aluminum sulfate, barium sulfate, calciumcarbonate, titanium oxide and calcium phosphate.

The organic composite filler includes fillers obtained by coatingsurfaces of the above inorganic fillers with polymerizable monomers bypolymerization and then milling the coated fillers. Specifically, theorganic composite filler includes a filler (TMPT.f) obtained by coatinga fine silica powder or zirconium oxide of the above inorganic fillerwith a polymerizable monomer composed mainly of trimethylolpropanetri(meth)acrylate (TMPT) by polymerization.

When the curable composition of the present invention is used as a resincement, particularly preferred as the component (e) is a filler whichcontains 40 to 80 parts by weight of a zirconium oxide filler having anaverage particle diameter of 0.05 to 10 μm, 10 to 80 parts by weight ofa spherical silica filler having an average particle diameter of 1 to 10μm and 10 to 30 parts by weight of an organic composite filler having anaverage particle diameter of 1 to 30 μm, preferably 5 to 30 μm. Further,as the above zirconium oxide filler, preferred is a filler which isobtained by coating zirconium oxide with a polymer soluble in thecomponent (b), e.g., PMMA or polyvinyl acetate (PVAc), and which has anaverage particle diameter of 1 to 30 μm, particularly 5 to 30 μm.

In time third curable composition of the present invention, on the basisof the total amount of the components (a), (b) and (c), time amount ofthe component (a) is 1 to 50% by weight, the amount of the component (b)is 1 to 98.99% by weight, and the amount of the component (c) is 0.01 to50% by weight. Further, on the basis of the total amount of thecomponents (a), (b), (c) and (e), the amount of the component (e) is 15to 85% by weight.

Further, the curable composition of the present invention may containboth the components (d) and (e). The curable composition of the presentinvention, which further contains both the components (d) and (e), willbe referred to as a fourth curable composition of the present invention.

It should be understood that the explanations already given with regardto the components (d) and (e) for the second and third curablecompositions can be directly applied to the components (d) and (e) forthe fourth curable composition.

In the fourth curable composition of the present invention, on the basisof the total amount of the components (a), (b) and (c), the amount ofthe component (a) is 1 to 50% by weight, the amount of the component (b)is 1 to 98.99% by weight, and the amount of the component (c) is 0.01 to50% by weight. Further, on the basis of the total amount of thecomponents (a), (b), (c) and (d), the amount of the component (d) is 3to 50% by weight, and on the basis of the total amount of the components(a), (b), (c), (d) and (e), the amount of the component (e) is 15 to 85%by weight.

Owing to the use of the component (e) in the third and fourth curablecompositions of the present invention, the viscosity of thesecompositions can be easily changed and these compositions can beadjusted to a viscosity in the range of from 100 to 30,000 cp widenmeasured at 37.5° C. Since, however, the third and fourth curablecompositions show handling properties different from those of the firstand second curable compositions in some cases, the third and fourthcurable compositions are preferably defined by the weight range of thecomponent (e) rather than the viscosity.

In the first to fourth curable compositions of the present invention,the above components (a) to (e) may be mixed in advance and applied to atooth. When a mixture of the above components might change in form andperformance to impair the effects of the present invention because ofstoring it for a long period of time, each component may be separatelystored. Or, these components may be divided to combinations as required,and stored, and these components may be mixed before use to prepare thecurable composition.

The method for storing the curable compositions includes a method inwhich the above components are divided into two groups such as a mixtureof the components (a/b(/d/e)) and the component (c) and a method inwhich the above components are divided into a mixture of the components(a/b(/d/e)) and a mixture of the components (b(/d/e)/c). These mixturesmay be placed in separate containers and prepared as a kit for providingthem as a commercial product. When the component (c) consists of twocomponents, either BPO or CQ and an amine, the above components aredivided into a mixture of the components (a/b/c (BPO or CQ)(/d/e)) and amixture of the components (b(/d/e)/c(amine, e.g., N,N-dimethylp-toluidine (to be abbreviated as DMPT))). Further, part or the whole ofthe component (c) may be contained in a tool to be used for applying acurable composition to a tooth surface, and in this case, the tool isbrought into contact with the components (a), (b), (d) and (e) toprepare the curable composition immediately before use, and the curablecomposition is applied to a tooth surface. Although not speciallylimited, the tool used for applying the curable composition to a toothsurface preferably includes a brush, a ball or cloth of fiber, and aball or piece of sponge.

That is, according to the present invention, there is provided a methodof applying any one of the curable compositions, which comprisesallowing a tool for applying a curable composition to a tooth surface tocontain part or the whole of the component (c), then bringing thecomponents (a), (b) and optionally (d) and a remaining component (c) ifany into contact with the tool to prepare the curable composition on thetool, and applying the curable composition to a tooth surfaceimmediately after the curable composition has been prepared.

In the above method, a time can be saved as compared with a method, forexample, in which a curable composition is divided into two portions andstored in two containers and the two portions are mixed just before use.Further, the curable composition can be used economically by bringing anecessary amount of the curable composition into contact with the toolsuch as a sponge without using a mixing container. The curablecomposition of the present invention is so applied to a tooth surfaceand then a dental restorative resin is applied thereon, whereby thedental restoration can be advantageously conducted.

According to the present invention, for achieving the above objects,second, there is further provided a primer composition comprising

(a) a polymerizable monomer having an acidic group in its molecule, and

(f) a solvent selected from the group consisting of an organic solventand an aqueous organic solvent.

The primer composition or tooth surface treating agent of the presentinvention can be used for treating a surface of enamel and dentin at thesame time, and is suitable for applying an adhesive material to a tooth.

In the tooth surface treating agent of the present invention, thecomponent (a) is a polymerizable monomer having an acidic group in itsmolecule. The polymerizable group of the above polymerizable monomerincludes a radical-polymerizable unsaturated group having a(meth)acryloyl group, a styryl group, a vinyl group or an allyl group.The above polymerizable monomer can be a monomer whose molecule containsat least one group selected from these polymerizable groups (apolymerizable group in polymerizable monomers to be describedhereinafter should be all interpreted in this sense). The polymerizablemonomer having an acidic group in its molecule may contain any one offunctional groups such as a carboxyl group, a phosphoric acid group, asulfonic acid group, a hydroxyl group, an amino group and a glycidylgroup.

The above polymerizable monomer as the component (a) includes thosedescribed with regard to the component (a) for the curable compositionof the present invention.

In the tooth surface treating agent of the present invention, thecomponent (f) is an organic solvent or an aqueous organic solvent. Theorganic solvent is selected from those which can uniformly dissolve ordisperse the component (a) or a component (g) to be described later.Further, the organic solvent is preferably miscible with water. Theorganic solvent includes alcohols such as methanol, ethanol (EtOH) andpropanol; ketones such as acetone and methyl ethyl ketone; ethers suchas tetrahydrofuran; and amides such as N,N-dimethylformamide. In view oftoxicity and stimulation to dental pulp, it is particularly preferred touse ethanol or acetone.

Further, the component (f) may contain water as described above. Thewater includes distilled water, ion-exchanged water and a physiologicalsaline solution. Distilled water and ion-exchanged water are preferred.The organic solvent as the component (f) therefore may be used as amixture thereof with water. In this case, particularly preferred is amixture of water with ethanol or a mixture of water with acetone.

In the tooth surface treating agent of the present invention, per 100parts by weight of the total amount of the components (a) and (f), theamount of the component (a) is 0.1 to 30 parts by weight, and the amountof the component (f) is 70 to 99.9 parts by weight. Preferably, theamount of the component (a) is 1 to 20 parts by weight, and the amountof the component (f) is 80 to 99 parts by weight.

In addition to the above components (a) and (f), the tooth surfacetreating agent of the present invention may further contain at least onemember selected from the group consisting of

(g) a polymerizable monomer copolymerizable with the above component(a), and

(c) a polymerization initiator.

File above component (g) is a polymerizable monomer which iscopolymerizable with the component (a). Although not specially limited,the above component (g) includes aliphatic acid esters of (meth)acrylicacid such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl(meth)acrylate, butyl (meth)acrylate, neopentyl glycol di(meth)acrylateand trimethylolpropane tri(meth)acrylate; polyethylene glycoldi(meth)acrylates such as ethylene glycol di(meth)acrylate, diethyleneglycol di(meth)acrylate, triethylene glycol di(meth)acrylate,pentaethylene glycol di(meth)acrylate, nonaethylene glycoldi(meth)acrylate and tetradecaethylene glycol di (meth)acrylate;polypropylene glycol di(meth)acrylates such as propylene glycoldi(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropyleneglycol di(meth)acrylate and nonapropylene glycol di(meth)acrylate;mono(meth)acrylates in which the (meth)acryloyl group of the abovepolyethylene glycol di(meth)acrylates or the above polypropylene glycoldi(meth)acrylates is replaced with a methyl group or an ethyl group;(meth)acrylates having a urethane bond such as an adduct of2-(meth)acryloyloxyethyl isocyanate, 2,2,4-trimethylhexamethylenediisocyanate or 1,3,5-trimethylhexamethylene diisocyanate with2-hydroxyethyl (meth)acrylate;2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propanes obtained by formingan adduct of bisphenol A with oxyethylene and further condensing theadduct and (meth)acrylic acid; styrene derivatives such as styrene,4-methylstyrene, 4-chloromethylstyrene and divinylbenzene; and vinylacetate. These polymerlzabale monomers may be used alone or incombination.

The component (g) is further selected from polymerizable monomers havinga hydroxyl group in their molecules. These polymerizable monomers, asmonomers having a (meth)acryloyl group, include hydroxylgroup-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate,2- or 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate,5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate,10-hydroxydecyl (meth)acrylate, 1,2- or 1,3- and 2,3-dihydroxypropane(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycolmono(meth)acrylate, pentaethylene glycol mono(meth)acrylate,polyethylene glycol mono(meth)acrylate and dipropylene glycolmono(meth)acrylate; hydroxyl group-containing (meth)acrylamides such asmethylol(meth)acrylamide, N-(meth)acryloyl-2,3-dihydroxypropylamine andN-(meth)acryloyl-1,3-dihydroxypropylamine; and adducts of glycidylmethacrylate with aliphatic or aromatic polyols (including phenol) suchas 2-hydroxy-3-phenoxypropyl (meth)acrylate (where it is methacrylate:HPPM), 2-hydroxy-3-naphthoxypropyl (meth)acrylate (where it ismethacrylate: HNPM) and an addition reaction product of 1 mol ofbisphenol A with 2 mol of glycidyl (meth)acrylate (where it ismethacrylate: GMA) (where the addition reaction product is methacrylate:Bis-GMA). The above polymerizable monomers may be used alone or incombination.

It should be understood that the explanations already given with regardto the polymerization initiator for the curable composition can beapplied to the polymerization initiator in the same manner as with theabove component (c).

In the tooth surface treating agent of the present invention, on thebasis of the total amount of the components (a), (f), (g) and (c),preferably, the amount of the component (a) is 0.1 to 30% by weight, theamount of the component (f) is 70 to 99.9% by weight, the amount of thecomponent (g) is 0 to 30% by weight, and the amount of the component (e)is 0 to 20% by weight. More preferably, the amount of the component (a)is 1 to 20% by weight, the amount of the component (f) is 50 to 97.95%by weight, the amount of the component (c) is 0.05 to 15% by weight, andthe amount of the component (g) is 1 to 15% by weight.

in the tooth surface treating agent of the present invention, the abovecomponents (a), (f), (g) and (e) may be mixed in advance and applied toa tooth. When a mixture of the above components may change in form andperformance to impair the effects of the present invention because ofstoring it for a long period of time, each component may be separatelystored, or these components may be divided to combinations as required,and stored, and these components may be mixed before use to prepare thetooth surface treating agent.

The method for storing the tooth surface treating agent includes amethod in which the above components are divided into two groups such asa mixture of the components (a/f/g) and the component (c) and a methodin which the above components are divided into a mixture of thecomponents (a/f/g) and a mixture of the components (f/c). The method ofdividing the components shall not be limited to the above combinations.These mixtures may be placed in separate containers and prepared as akit for providing them as a commercial product. The tooth surfacetreating agent of the present invention is applied to a tooth surfaceand then a dental restorative resin and/or a tooth-bonding curablecomposition are/is applied thereon, whereby the dental restoration canbe advantageously conducted.

When the tooth surface treating agent of the present invention and thecurable composition of the present invention are used in combination,there is provided a method of treating a tooth surface, which comprisesapplying the tooth surface treating agent of the present invention to atooth surface and then applying the curable composition of the presentinvention.

The above method of treating a tooth surface is preferably carried outin any one of the following two embodiments.

In the first preferred embodiment, the method of treating a toothsurface comprises applying a primer composition comprising

(a') 1 to 30% by weight of at least one member selected from4-(meth)acryloyloxyethyltrimellitic acid or an anhydride thereof andN-(meth)acryloylaminosalicylic acid,

(f') 30 to 90% by weight of at least one member selected from the groupconsisting of an aqueous ethanol or an aqueous acetone,

(g') 1 to 20% by weight of a (meth)acrylate having an oxyalkylene group,and

(c') 1 to 20% by weight of an aromatic sulfonate

to a tooth surface, and applying a visible lightcurable compositioncomprising

(n') 1 to 30% by weight of at least one member selected from4-(meth)acryloyloxyethyltrimellitic acid or an anhydride thereof andN-(meth)acryloylaminosalicylic acid,

(b') 30 to 90% by weight of at least one member selected from the groupconsisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, glycerol (meth)acrylate, erythritol (meth)acrylate andpoly(meth)acrylate of an polyepoxy compound of bisphenol,

(c') 0.1 to 5% by weight of a combination of d,l-camphorquinone which isa visible light sensitizer and at least one reducing agent selected fromN-phenylglycine, N,N-dialkylaminobenzoic acid and aromatic sulfonate,and

(d') 3 to 20% by weight of a (meth)acrylate having an oxyalkylene groupin its molecule, and having a viscosity in the range of from 100 to30,000 cp when measured at 37.5° C.

In the second preferred embodiment, the method of treating a toothsurface comprises applying a primer composition comprising

(a') 1 to 30% by weight of at least one member selected from4-(meth)acryloyloxyethyltrimellitic acid or an arthydride thereof andN-(meth)acryloylaminosalicylic acid,

(f') 30 to 90% by weight of at least one member selected from the groupconsisting of an aqueous ethanol or an aqueous acetone, and

(g') 1 to 20% by weight of a (meth)acrylate having an oxyalkylene group,and applying a room temperature curable composition comprising

(a') 1 to 30% by weight of at least one member selected from4-(meth)acryloyloxyethyltrimellitic acid or an anhydride thereof andN-(meth)acryloylaminosalicylic acid,

(b') 10 to 60% by weight of at least one member selected from the groupconsisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, glycerol (meth)acrylate, erythritol (meth)acrylate andpoly(meth)acrylate of an polyepoxy compound of bisphenol,

(c') 0.1 to 10% by weight of a combination of at least one memberselected from d,l-camphorquinone, an organic peroxide and an inorganicperoxide with at least one reducing agent selected from N-phenylglycine,N,N-dimethyl-p-toluidine, N,N-diethanol-p-toluidine,N,N-dialkylaminobenzoic acid and aromatic sulfonate,

(d') 10 to 60% by weight of a (meth)acrylate having an oxyalkylene groupin its molecule, and

(e') a filler containing any one of 10 to 60% by weight of a zirconiumoxide filler having an average particle diameter of 0.05 to 10 μm, 5 to80% by weight of a spherical silica filler having an average particlediameter of 1 to 10 μm and 5 to 30% by weight of an organic compositefiller having an average particle diameter of 1 to 30 μm.

The present invention will be detailed hereinafter with reference toExamples.

In the evaluation of adhesion strength, a curable composition wasprepared as a bonding material for a composite resin or as a resincement and evaluated as follows.

Fresh bovine lower-jaw anterior teeth, which had been taken out, frozenin water and stored, were used as tooth samples. A thawed bovine toothwas ground with a rotary grinder ECOMET-III (supplied by BUEHLER) withpouring water under manual pressure up to a water-resistant emery paper#600 so that the enamel and dentin were exposed, whereby a smoothsurface was prepared. Water was removed from the grounded bovine toothwith an air gun. Immediately thereafter, a Cellophane tape having a holehaving a diameter of 5.1 mm was attached to the bovine tooth to definean adhesion area, and the bovine tooth was again immersed in water.

The bovine tooth was allowed to stand in the water for at least 1minute, and then taken out. Water was lightly wiped off from theadhesion surface with a ball of cotton. The adhesion surface still hadsome water, and was used as a wet surface for an adhesion test.

(1) Application as bonding material for composite resin

A curable composition was applied to a sponge (accessory to Super BondC&B, supplied by Sun Medical Co., Ltd), and moderately exposed to airblowing from an air gun for about 5 seconds. The curable composition wasexposed to visible light from a visible light irradiation apparatus(Translux CL, Knlzer) for 20 seconds to cure the composition. Acardboard with a ring hole having an internal diameter of 5.1 mm and adepth of 1 mm and having an adhesive on one surface was placed andfixed, and this hole was filled with a composite resin (Silux Plus, 3M),and coated with a polyester film having a thickness of 50 μm. Thecomposite resin was exposed through this film to visible light from avisible light irradiation apparatus (Translux CL, Kulzer) for 40 secondsto cure the composite resin, and the film was peeled off. An acryl rodwas planted upright with METAFAST (supplied by Sun Medical Co., Ltd) andallowed to stand for 15 minutes.

(2) Application as resin cement

Liquid component(s) and powder component(s) separately stored for thethird curable composition of the present invention were mixed in aDappen glass just before use or fully kneaded on kneading paper. Then,the resultant mixture was applied to the defined adhesion surface, andan acryl rod was planted upright and allowed to stand for 15 minutes.

The sample prepared by the above method (1) or (2) was immersed in waterat 37° C. for 24 hours, and then subjected to a tension adhesion test(cross head speed 2 mm/min.).

The interface between the tooth and the composite resin was measured fora gap by the following method, while tills measurement was not carriedout when the resin cement was used.

For determining the full contact between a tooth and a restorativematerial, a thawed bovine tooth was ground with a rotary grinderECOMET-III (supplied by BUEHLER) with pouring water under manualpressure up to a water-resistant emery paper #600 so that the enamel anddentin were exposed, whereby a smooth surface was prepared. A φ3×3 mmcavity was formed with a diamond point with pouring water. A curablecomposition of the present invention was applied to a surface of thecavity with a sponge, exposed to moderate air blowing with an air gun,and exposed to visible light from a visible light irradiation apparatus(Translux CL, Kulzer) for 20 seconds to cure the composition. Further, acomposite resin was filled in the cavity, and similarly exposed tovisible light for 40 seconds to cure the composite resin. The surfacewas made smooth by grinding the surface up to #600 with pouring water,and then, the bovine tooth was immersed in a basic fuchsin aqueoussolution for 1 minute and washed with water. The bovine tooth was driedwith an air gun and measured for a gap with an optical microscope, andthe coloring in a portion where the gap was formed was visually observedto determine the formation of the gap.

For the viscosity of a curable composition, 1.0 cc of the curablecomposition was measured with a viscometer TYPE-EHD (TOKIMEC Co., Ltd)at, 37.5° C.

EXAMPLE 1

A curable composition as a bonding material or a composite resin wasprepared as follows. A solution containing 58.5 parts by weight of2-hydroxyethyl methacrylate (HEMA), 35 parts by weight of VR90 (ShowaKobunshi K.K.), 6.5 parts by weight of 4-MET and 0.5 part by weight ofd,l-camphorquinone (CQ) was prepared, and placed in a shaded droppingbottle. Separately, 0.3 part by weight of sponge chips S (φ2×3 ram) asan accessory to Superbond D Liner Plus and 0.5 part by weight ofN-phenyglycine (NPG) were placed in a polyethylene bag and fully shakenallow the sponge chips to contain NPG. One drop of the solution wastaken from the dropping bottle onto a Dappen dish, and the solution wasinfiltrated into one sponge chip containing NPG and applied to a toothsurface. The composition was tested for adhesion to show that theadhesion strength to a dentin was 76±38 kgf/cm², and no formation of agap was observed.

When the monomer components and NPG as the polymerization initiatorcomponent were divided as above, the curable composition of the presentinvention was storable for a long period of time without any change inform. Further, the adhesion procedures were simple and the time requiredfor these procedures was decreased as compared with a conventionalmethod in which components were divided and stored and they were mixedjust before use and then applied.

EXAMPLE 2

A curable composition as a bonding material for a composite resin wasprepared as follows. 45.5 Parts by weight of HEMA, 35 parts by weight ofVR90, 6.5 parts by weight of triethylene glycol dimethacrylate (3G), 6.5parts by weight of 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane(2.6E, Shin-Nakamura Kagaku K.K.), 6.5 parts by weight of 4-MET, 0.5part by weight of CQ and 0.5 part by weight of NPG were mixed mixed toprepare solution. As soon as the solution was prepared, the solution wastested for adhesion to show that the adhesion strength to dentin was99+49 kgf/cm² and no formation of a gap was observed. The solutioncontaining NPG gelled about 1 day after being prepared, and was nolonger usable.

EXAMPLE 3

A curable composition as a bonding material for a composite resin wasprepared as follows. 52.5 Parts by weight of HEMA, 12.5 parts by weightof VR90, 7.5 parts by weight of 3G, 7.5 parts by weight of 2.6E, 7.5parts by weight of 4-MET, 12.5 parts by weight of polyvinyl acetate(PVAc), 0.5 part by weight of CQ and 0.5 part by weight of NPG weremixed to prepare solution. As soon as the solution was prepared, thesolution was tested for adhesion to show that the adhesion strength todentin was 77±18 kgf/cm², and no formation of a gap was observed.EXAMPLE 4

A curable composition was obtained in the same manner as in Example 2except that 4-MET was , replaced with 4-META (the composition had aviscosity of 280 cP). The curable composition showed that the adhesionstrength to dentin was 78±18 kgf/cm², and no formation of a gap wasobserved.

EXAMPLE 5

A curable composition as a resin cement was a combination of thefollowing liquid and powder components. A liquid component: 60 parts byweight of HEMA, 30 parts by weight of 2-hydroxy-3-phenoxypropylmethacrylate (HPPM), 4 parts by weight: of 4-MET, 5 parts by weight ofN-methacryloyl 5-aminosalicylic acid (5-MASA) and 1 part by weight ofbenzoyl peroxide (BPO). A powder component: 60 parts by weight of azirconium oxide filler (ZrO₂, average particle diameter 2 μm) coatedwith 10% by weight of PMMA, 20 parts by weight of a spherical silicafiller (SiO₂) having an average particle diameter of 5 μm, 20 parts byweight of an organic composite filler (TMPT. f) having an averageparticle diameter of 20 μm, prepared by coating a silica filler havingan average participle diameter of 0.04 μm with trimethylolpropanetrimethacrylate (TMPT) by preliminary polymerization and milling theresultant polymer, and 2 parts by weight of NPG. 0.09 Parts by weight ofthe liquid component and 0.13 part by weight of the powder component wasmixed and kneaded on a kneading paper sheets, and 1, minute after thekneading, the mixture (curable composition) was used for an adhesiontest. The composition showed that the adhesion strength to dentin was57±22 kgf/cm².

EXAMPLE 6

A curable composition was prepared in the same manner as in Example 5except that HPPM for a liquid component was replaced with TMPT. Thecomposition showed that the adhesion strength to dentin was 42±20kgf/cm².

EXAMPLE 7

A curable composition was prepared in the same manner as in Example 5except that HPPM for a liquid component was replaced with an adduct(UDMA) of 1 mol of 2,2,4-trimethylhcxamethylene diisocyanate with 2 molof HEMA. The composition showed that the adhesion strength to dentin was69±25 kgf/cm².

EXAMPLE 8

A curable composition was prepared in the same manner as in Example 5except that HPPM for a liquid component was replaced with VR90. Thecomposition showed that the adhesion strength to dentin was 40±8kgf/cm².

EXAMPLE 9

A curable composition was prepared in the same manner as in Example 5except that HPPM for a liquid component was replaced with 3G and thatthe amount of NPG for a powder component was changed to 1 part byweight. The composition showed that the adhesion strength to dentin was50±9 kgf/cm².

EXAMPLE 10

A dentin surface was etched with a 10 wt % citric acid aqueous solutioncontaining 3 wt % ferric chloride and washed with water. Then, water wasremoved with a ball of cotton, and the same curable composition as thatprepared in Example 9 was applied to the dentin surface and tested inthe same manner as in Example 9. The composition showed that theadhesion strength to dentin was remarkably high, as high as 107 ±15kgf/cm².

                                      TABLE 1                                     __________________________________________________________________________       Curable composition         Adhesion                                       Ex.                                                                              (parts by weight)      Viscosity                                                                          strength                                       No.                                                                              A    B    C  D    E    (cP) (kgf/cm.sup.2)                                                                      GAP                                      __________________________________________________________________________    1  4-MET                                                                              HEMA CQ --   --    180 76 ± 88                                                                          No                                               VR90 NPG                                                              2  4-MET                                                                              HEMA CQ 3G   --    230 99 ± 49                                                                          No                                               VR90 NPG                                                                              2.6E                                                          3  4-MET                                                                              HEMA CQ 3G   PVAc  860 77 ± 18                                                                          No                                               VR90 NPG                                                                              2.6E                                                          4  4-META                                                                             HEMA CQ 3G   --    280 78 ± 18                                                                          No                                               VR90 NPG                                                                              2.6E                                                          5  4-MET                                                                              HEMA BPO                                                                              --   ZrO.sub.2                                                                          5300 57 ± 22                                                                          --                                          5-MASA                                                                             HPPM NPG     SiO.sub.2                                                                     TMPT · f                                        6  4-MET                                                                              HEMA BPO                                                                              TMPT ZrO.sub.2                                                                          7800 42 ± 20                                                                          --                                          5-MASA    NPG     SiO.sub.2                                                                     TMPT · f                                        7  4-MET                                                                              HEMA BPO                                                                              UDMA ZrO.sub.2                                                                          7000 69 ± 25                                                                          --                                          5-MESA                                                                             VR90 NPG     SiO.sub.2                                                                     TMPT · f                                        8  4-MET                                                                              HEMA BPO                                                                              --   ZrO.sub.2                                                                          9500 40 ± 8                                                                           --                                          5-MASA                                                                             VR90 NPG     SiO.sub.2                                                                     TMPT · f                                        9  4-MET                                                                              HEMA BPO                                                                              3G   ZrO.sub.2                                                                          7200 50 ± 9                                                                           --                                          5-MASA    NPG     SiO.sub.2                                                                     TMPT · f                                        10 4-MET                                                                              HEMA BPO                                                                              3G   ZrO.sub.2                                                                          7900 107 ± 15                                                                         --                                          5-MASA    NPG     SiO.sub.2 (etching)                                                           TMPT · f                                        __________________________________________________________________________

A primer of the present invention was applied to an area-defined surfacewith a sponge (accessory to Super bond C&B, supplied by Sun Medical),and allowed to stand for 30 seconds. Superfluous liquid was removed byblowing air to the surface for about 5 seconds to prepare a treatedsurface. This treated surface was bonded using the curable compositionprepared in Example 2 or 9.

The curable composition obtained in Example 2 was used as a bondingmaterial for a composite resin for the adhesion test, and the curablecomposition obtained in Example 9 was used as a resin cement for theadhesion test.

The opened state of dental tubules was observed in the followingprocedures. That is, in the method of evaluation of adhesion, a toothsurface treating agent was applied to a ground dentin surface andsuperfluous liquid was removed by blowing air. Thereafter, the dentinsurface was observed through an optical microscope to see the open stateof the dental tubules.

EXAMPLE 11

A solution containing 20 parts by weight of 4-MET and 80 parts by weightof ethanol (EtOH) was used as a tooth surface treating agent, and thesame curable composition as that obtained in Example 2 was used andadhesion strengths to enamel and to dentin were measured. As a result,the composition showed that the adhesion strength to enamel was 65±8kgf/cm² and that the adhesion strength to dentin was 73±15 kgf/cm². Whenthe dental tubules were observed through an optical microscope after thedentin was treated, no opening of the tubules was observed. Further, noformation of a gap was found.

EXAMPLE 12

A solution containing 20 parts by weight of 4-MET, 20 parts by weightoff distilled water (H₂ O) and 80 parts by weight of EtOH was used as atooth surface treating agent, and the same curable composition as thatobtained in Example 2 was used, and adhesion strengths to enamel and todentin were measured. As a result, the composition showed that theadhesion strength to enamel was 96±20 kgf/cm² and that the adhesionstrength to dentin was 101±20 kgf/cm². When the dental tubules wereobserved through an optical microscope after the dentin was treated, noopening of the tubules was observed. Further, no formation of a gap wasfound.

EXAMPLE 13

A solution containing 15 parts by weight of 4-MET, 6 parts by weight ofN-methacryioyl-5-aminosalicylic acid (5-MASA), 20 parts by weight of H₂O and 80 parts by weight of troll was used as a tooth surface treatingagent, and the same curable composition as that obtained in Example 2was used, and adhesion strengths to enamel and to dentin were measured.As a result, the composition showed that the adhesion strength to enamelwas 64±24 kgf/cm² and that the adhesion strength to dentin was 90±28kgf/cm². When the dental tubules were observed through an opticalmicroscope after the dentin was treated, no opening of the tubules wasobserved. Further, no formation of a gap was found.

EXAMPLE 14

A solution containing 20 parts by weight of 4-MET, 42.5 parts by weightof H₂ O and 37.5 parts by weight of EtOH was used as a tooth surfacetreating agent, and the same curable composition as that obtained inExample 2 was used, and adhesion strengths to enamel and to dentin weremeasured. As a result, the composition showed that the adhesion strengthto enamel was 93±18 kgf/cm² and that the adhesion strength to dentin was111±23 kgf/cm². When the dental tubules were observed through an opticalmicroscope after the dentin was treated, no opening of the tubules wasobserved. Further, no formation of a gap was found.

EXAMPLE 15

A solution containing 10 parts by weight of 4-MET, 40 parts by weight ofEtOH, 45 parts by weight of H₂ O and 5 parts by weight of nonaethyleneglycol dimethacrylate (9G) was used as a tooth surface treating agent,and the same curable composition as that obtained in Example 2 was used,and adhesion strengths to enamel and to dentin were measured. As aresult, the composition showed that the adhesion strength to enamel was70±12 kgf/cm² and that the adhesion strength to dentin was 83±7 kgf/cm².When the dental tubules were observed through an optical microscopeafter the dentin was treated, no opening of the tubules was observed.Further, no formation of a gap was found.

EXAMPLE 16

A solution containing 10 parts by weight of 4-MET, 40 parts by weight ofEtOH, 45 parts by weight, of H₂ O and 5 parts by weight of polyethyleneglycol dimethacrylate (23G) was used as a tooth surface treating agent,and the same curable composition as that obtained in Example 9 was used,and adhesion strengths to enamel and to dentin were measured. As aresult, the composition showed that the adhesion strength to enamel was102±18 kgf/cm² and that the adhesion strength to dentin was 109±33kgf/cm². When the dental tubules were observed through an opticalmicroscope after the dentin was treated, no opening of the tubules wasobserved.

EXAMPLE 17

A solution containing 10 parts by weight of 4-META, 5 parts by weight of5-MASA, 40 parts by weight of EtOH, 40 parts by weight of H₂ O and 5parts by weight off 23G was used as a tooth surface treating agent, andthe same curable composition as that obtained in Example 9 was used, andadhesion strengths to enamel and to dentin measured. As a result, thecomposition showed that the adhesion strength to enamel was 108±32kgf/cm² and that the adhesion strength to dentin was 110±37 kgf/cm².When the dental tubules were observed through an optical microscopeafter the dentin was treated, no opening of the tubules was observed.

EXAMPLE 18

A solution containing 20 parts by weight of 4-MET, 20 parts by weight ofEtOH, 70 parts by weight of H₂ O and 0.05 part by weight of CQ was usedas a tooth surface treating agent, and the same curable composition asthat obtained in Example 2 was used, and adhesion strengths to enameland to dentin were measured. As a result, the composition showed thatthe adhesion strength to enamel was 51±26 kgf/cm² and that the adhesionstrength to dentin was 62±18 kgf/cm². When the dental tubules wereobserved through an optical microscope after the dentin was treated, noopening of the tubules was observed. Further, no formation of a gap wasfound.

EXAMPLE 19

A solution containing 5 parts by weight of 4-MET, 45 parts by weight ofEtOH, 48 parts by weight of H₂ O, 2 parts by weight of 3G, 0.05 part byweight of CQ and 0.1 part by weight of N,N-dimethylaminobenzoic acid(DEABA) was used as a tooth surface treating agent, and the same curablecomposition as that obtained in Example 2 was used, and adhesionstrengths to enamel and to dentin were measured. As a result, thecomposition showed that the adhesion strength to enamel was 44±14kgf/cm² and that the adhesion strength to dentin was 51±14 kgf/cm². Whenthe dental tubules were observed through an optical microscope after thedentin was treated, no opening of the tubules was observed. Further, noformation of a gap was found.

EXAMPLE 20

A solution containing 10 parts by weight of 4-MET, 40 parts by weight ofEtOH, 45 parts by weight of H₂ O, 5 parts by weight of nonaethyleneglycol dimethacrylate (9G) and 0.05 part by weight of CQ was used as atooth surface treating agent, and the same curable composition as thatobtained in Example 2 was used, and adhesion strengths to enamel and todentin were measured. As a result, the composition showed that theadhesion strength to enamel was 93±8 kgf/cm² and that the adhesionstrength to dentin was 113±13 kgf/cm². When the dental tubules wereobserved through an optical microscope after the dentin was treated, noopening of the tubules was observed. Further no formation of a gap wasfound.

EXAMPLE 21

A solution containing 10 parts by weight of 4-MET, 40 parts by weight ofEtOH, 45 parts by weight of H₂ O, 5 parts by weight of 9G, 0.05 part byweight of CQ and 5 part by weight of NPG was used as a tooth surfacetreating agent, and the same curable composition as that obtained inExample 2 was measured for adhesion strength to enamel and dentin. As aresult, the composition showed that the adhesion strength to enamel was70±10 kgfl/cm² and that the adhesion strength to dentin was 87±21kgf/cm². When the dental tubules were observed through an opticalmicroscope after the dentin was treated, no opening of the tubules wasobserved. Further, no formation of a gap was found.

EXAMPLE 22

A solution containing 10 parts by weight of 4-MET, 40 parts by weight ofEtOH, 45 parts by weight of H₂ O, 5 parts by weight of 9G and 0.05 partby weight of CQ was used as a tooth surface treating agent, and the samecurable composition as that obtained in Example 2 was used, and adhesionstrengths to enamel and to dentin were measured. As a result, thecomposition showed that the adhesion strength to enamel was 89±15kgf/cm² and that the adhesion strength to dentin was 99±11 kgf/cm². Whenthe dental tubules were observed through an optical microscope after thedentin was treated, no opening of the tubules was observed. Further, noformation of a gap was found.

EXAMPLE 23

A solution containing 20 parts by weight of 4-MET, 65 parts by weight ofEtOH and 15 parts by weight of H₂ O, and a solution containing 85 partsby weight of H₂ O, 10 parts by weight of EtOH and 5 parts by weight ofsodium benzenesulfonate (BSNa) were mixed in equal amounts just beforeuse. The resultant mixture was used as a tooth surface treating eatingagent, and the same curable composition as that obtained in Example 9was used, and adhesion strengths to enamel and to dentin were measured.As a result, the composition showed that the adhesion strength to enamelwas 118±38 kgf/cm² and that the adhesion strength to dentin was 115±19kgf/cm². When the dental tubules were observed through an opticalmicroscope after the dentin was treated, no opening of the tubules wasobserved.

EXAMPLE 24

A solution containing 20 parts by weight of 4-META, 60 parts by weightof EtOH, 15 parts by weight of H₂ O and 4 parts by weight of 23G, and asolution containing 5 parts by weight of sodium ptoluenesulflnate(pTSNa), 10 parts by weight of EtOH, 80 parts by weight of H₂ O and 5parts by weight of 23G were mixed in equal amounts just before use. Theresultant mixture was used as a tooth surface treating agent, and thesame curable composition as that obtained in Example 2 was used, andadhesion strengths to enamel and to dentin were measured. As a result,the composition showed that the adhesion strength to enamel was 129±27kgf/cm² and that the adhesion strength to dentin was 128±16 kgf/cm².When the dental tubules were observed through an optical microscopeafter the dentin was treated, no opening of the tubules was observed.Further, no formation of a gap was found.

                                      TABLE 2                                     __________________________________________________________________________       Primer composition                                                                             Curable                                                                            Opening                                                                            Adhesion                                        Ex.                                                                              (parts by weight)                                                                              compo-                                                                             of dental                                                                          strength                                        No.                                                                              F    G   H  J    sition                                                                             tubules                                                                            (kgf/cm.sup.2)                                                                       GAP                                      __________________________________________________________________________    11 4-MET                                                                              EtOH                                                                              -- --   Example                                                                            No   E: 65 ± 8                                                                         No                                                           2         D: 73 ± 15                                   12 4-MET                                                                              H.sub.2 O                                                                         -- --   Example                                                                            No   E: 96 ± 20                                                                        No                                               EtOH        2         D: 101 ± 20                                  13 4-MET                                                                              H.sub.2 O                                                                         -- --   Example                                                                            No   E: 64 ± 24                                                                        No                                          5-MASA                                                                             EtOH        2         D: 90 ± 28                                   14 4-META                                                                             H.sub.2 O                                                                         -- --   Example                                                                            No   E: 93 ± 18                                                                        No                                               EtOH        2         D: 111 ± 23                                  15 4-MET                                                                              H.sub.2 O                                                                         9G --   Example                                                                            No   E: 70 ± 12                                                                        No                                               EtOH        2         D: 83 ± 7                                    16 4-MET                                                                              H.sub.2 O                                                                         23G                                                                              --   Example                                                                            No   E: 102 ± 18                                                                       --                                               EtOH        9         D: 109 ± 33                                  17 4-META                                                                             H.sub.2 O                                                                         23G                                                                              --   Example                                                                            No   E: 108 ± 32                                                                       --                                               EtOH        9         D: 110 ± 37                                  18 4-MET                                                                              H.sub.2 O                                                                         -- CQ   Example                                                                            No   E: 51 ± 26                                                                        No                                               EtOH        2         D: 62 ± 18                                   19 4-MET                                                                              H.sub.2 O                                                                         3G CQ   Example                                                                            No   E: 44 ± 14                                                                        No                                               EtOH   DEABA                                                                              2         D: 51 ± 14                                   20 4-MET                                                                              H.sub.2 O                                                                         9G CQ   Example                                                                            No   E: 93 ± 8                                                                         No                                               EtOH        2         D: 113 ± 13                                  21 4-MET                                                                              H.sub.2 O                                                                         9G CQ   Example                                                                            No   E: 70 ± 10                                                                        No                                               EtOH   NPG  2         D: 87 ± 21                                   22 4-META                                                                             H.sub.2 O                                                                         9G CQ   Example                                                                            No   E: 89 ± 15                                                                        No                                               EtOH        2         D: 99 ± 11                                   23 4-MET                                                                              H.sub.2 O                                                                         -- BSNa Example                                                                            No   E: 118 ± 38                                                                       No                                               EtOH        9         D: 115 ± 19                                  24 4-MET                                                                              H.sub.2 O                                                                         23G                                                                              pTSNa                                                                              Example                                                                            No   E: 129 ± 27                                                                       No                                          5-MASA                                                                             EtOH        2         D: 128 ± 16                                  __________________________________________________________________________

COMPARATIVE EXAMPLE 1

A curable composition as a bonding material for a composite resin wasprepared in the same manner as in Example 1 except that HEMA and VR90were replaced with methyl methacrylate (MMA) and UDMA. As a result,while a test sample was immersed in water, it was peeled off.

COMPARATIVE EXAMPLE 2

A curable composition as a bonding material for a composite resin wasprepared in the same manner as in Example 3 except that HEMA and VR90were replaced with MMA and UDMA (viscosity; 230 cP). As a result, whilea test sample was immersed in water, it was peeled off.

COMPARATIVE EXAMPLE 3

A curable composition as a bonding material for a composite resin wasprepared in the same manner as in Example 3 except that a solution(viscosity: 230 cP) containing neither CQ nor NPG as a polymerizationinitiator (c) component was used. As a result, while a test sample wasimmersed in water, it was peeled off.

COMPARATIVE EXAMPLE 4

A curable composition as a bonding material for a composite resin wasprepared in the same manner as in Example 3 except that a solution(viscosity: 230 cP) containing no polymerizable monomer (a) componenthaving an acidic group in its molecule was used. As a result, noformation of a gap was found, while the adhesion strength to dentin wasvery low, as low as 23 ±13 kgf/cm².

COMPARATIVE EXAMPLE 5

A curable composition as a resin cement was prepared in the same manneras in Example 5 except that HEMA and HPPM as the polymerizable monomer(b) component containing a hydroxyl group in its molecule were replacedwith UDMA. As a result, while a test sample was immersed ill water, itwas peeled off.

COMPARATIVE EXAMPLE 6

A curable composition as a resin cement was prepared in the same manneras in Example 6 except that no polymerization initiator (c) componentwas used, and the curable composition was tested for adhesion. As aresult, the curable composition did not undergo curing, and while a testsample was immersed in water, it was peeled off.

COMPARATIVE EXAMPLE 7

A curable composition as a resin cement was prepared in the same manneras in Example 9 except that no polymerizable monomer (a) componentcontaining an acidic group in its molecule was used, and the curablecomposition was tested for adhesion. As a result, the composition showedthat the adhesion strength to dentin was low, as low as 38±21 kgf/cm².

                                      TABLE 3                                     __________________________________________________________________________    Comp.                                                                             Curable composition         Adhesion                                      Ex. (parts by weight)      Viscosity                                                                          strength                                      No. A    B    C  D    E    (cP) (kgf/cm.sup.2)                                                                      GAP                                     __________________________________________________________________________    1   4-MET                                                                              --   CQ MMA  --   120  0     yes                                                   NPG                                                                              UDMA                                                         2   4-MET                                                                              --   CQ 3G   PVAc 230  0     yes                                                   NPG                                                                              2.6E                                                                          MMA                                                                           UDMA                                                         3   4-MET                                                                              HEMA -- 3G   PVAc 230  0     yes                                              VR90    2.6E                                                         4   --   HEMA CQ 9G   PVAc 230  23 ± 13                                                                          No                                               VR90 NPG                                                                              2.6E                                                         5   4-MET                                                                              --   BPO                                                                              UDMA ZrO.sub.2                                                                          7900 0     --                                          5-MASA    NPG     SiO.sub.2                                                                     TMPT · f                                       6   4-MET                                                                              HEMA -- TMPT ZrO.sub.2                                                                          7600 Not cured                                                                           --                                          5-MASA            SiO.sub.2                                                                     TMPT · f                                       7   --   HEMA BPO                                                                              3G   ZrO.sub.2                                                                          7700 38 ± 21                                                                          --                                                    NPG     SiO.sub.2                                                                     TMPT · f                                       __________________________________________________________________________

COMPARATIVE EXAMPLE 8

An adhesion test was carried out in the same manner as in Example 11except that 4-MET as a polymerizable monomer containing an acidic groupin its molecule was omitted from the tooth surface treating agent. As aresult, while a test sample for adhesion to enamel was immersed in waterit was peeled off. The adhesion strength to dentin was 20±8 kgf/cm², ormuch lower than that in Example 11. The formation of a gap was found.

COMPARATIVE EXAMPLE 9

A composition was prepared in the same manner as in Example 11 exceptthat EtOH as an organic solvent was omitted from the tooth surfacetreating agent. In this case, 4-MET was not dissolved since it was asolid, and no adhesion test was carried out.

COMPARATIVE EXAMPLE 10

A composition was prepared in the same manner as in Example 15 exceptthat EtOH as an organic solvent was omitted from the tooth surfacetreating agent. In this case, 4-MET was not dissolved since it was asolid, and no adhesion test was carried out.

COMPARATIVE EXAMPLE 11

An adhesion test was carried out in the same manner as in Example 11except that the tooth surface treating agent was replaced with acommercially available total etching agent and that the applied totaletching agent was not washed with water but airdried. A tooth surfacetreating agent (Green) belonging to Super bond C&B (Sum Medical Co.,Ltd) was used as the above total etching agent. As a result, when dentaltubules were observed through an optical microscope after the treatmentto dentin, all the dental tubules were opened. Further, while a testsample was immersed in water, rods bonded to enamel and dentin were allpeeled off, or not at all bonded.

COMPARATIVE EXAMPLE 12

An adhesion test was carried out in the same manner as in Example 11except that the tooth surface treating agent was replaced with a primerbelonging to a commercially available. Super bond D liner Plus (SunMedical). As a result, the adhesion strength to enamel was as low as48±21 kgf/cm², and the adhesion strength to dentin was as low as 53±19kgf/cm². when dental tubules were observed through an optical microscopeafter the treatment, no opening of dental tubules was found, while theformation of a gap was found.

COMPARATIVE EXAMPLE 13

An adhesion test was carried out in the same manner as in Example 18except that 4-MET as a polymerizable monomer containing an acidic groupin its molecule was omitted from the tooth surface treating agent. As aresult, while a test sample for adhesion to enamel was immersed inwater, it was peeled off. The adhesion strength to dentin was 18±10kgf/cm², or much lower than that in Example 18.

COMPARATIVE EXAMPLE 14

An attempt was made to prepare a solution as a tooth surface treatingagent in the same manner as in Example 18 except that EtOH as an organicsolvent was omitted from the composition shown in Example 18. In thiscase the mixture underwent phase separation, and no solution was formed.

COMPARATIVE EXAMPLE 15

An adhesion test was carried out in the same manner as in Example 20except that CQ as a polymerization initiator was omitted from thecomposition as a tooth surface treating agent shown in Example 20. As aresult the adhesion strength to enamel was 70±12 kgf/cm², and theadhesion strength to dentin was 83±7 kgf/cm², which values were low ascompared with those in Example 20.

COMPARATIVE EXAMPLE 16

An adhesion test was carried out in the same manner as in Example 16except that 4-MET as a polymerizable monomer containing an acidic groupin its molecule was omitted from the tooth surface treating agent. As aresult, while a test sample for adhesion to enamel was immersed inwater, it was peeled off. The adhesion strength to dentin was 52±13kgf/cm², or much lower than that in Example 16.

                                      TABLE 4                                     __________________________________________________________________________    Comp.                                                                              Primer composition                                                                          Curable                                                                            Opening                                                                            Adhesion                                         Ex.  (parts by weight)                                                                           compo-                                                                             of dental                                                                          strength                                         No.  F   G   H  J  sition                                                                             tubules                                                                            (kgf/cm.sup.2)                                                                      GAP                                        __________________________________________________________________________     8   --  EtOH                                                                              -- -- Example                                                                            No   E: 0  yes                                                           2         D: 20 ± 8                                      9   4-MET                                                                             --  -- -- Example                                                                            --   Not   --                                                            2         usable                                           10   4-MET                                                                             --  9G -- Example                                                                            --   Not dis-                                                                            --                                                            2         solved                                           11   Super bond C & B                                                                            Example                                                                            yes  E: 0  yes                                             Surface treating agent                                                                      2         D: 0                                                  (not washed with water)                                                  12   Super bond D liner plus                                                                     Example                                                                            No   E: 48 ± 21                                                                       yes                                             primer        2         D: 53 ± 19                                    13   --  H.sub.2 O                                                                         -- CQ Example                                                                            No   E: 0  yes                                                 EtOH      2         D: 18 ± 10                                    14   4-MET                                                                             --  -- CQ --   --   Not dis-                                                                            --                                                                      soved                                            15   4-MET                                                                             H.sub.2 O                                                                         9G -- Example                                                                            No   E: 70 ± 12                                                                       --                                                  EtOH      2         D: 83 ± 7                                     16   --  H.sub.2 O                                                                         23G                                                                              -- Example                                                                            No   E: 0  --                                                  EtOH      9         D: 52 ± 13                                    __________________________________________________________________________

What is claimed is:
 1. A method of treating a tooth surface, whichcomprises applying a primer composition comprising (A) (a) apolymerizable monomer having an acidic group in its molecule, and (f) asolvent selected from the group consisting of an organic solvent and anaqueous organic solvent to a tooth surface and then applying a curablecomposition comprising(A1) (a) a polymerizable monomer having an acidicgroup in its molecule, (b) a polymerizable monomer having a hydroxylgroup in its molecule, (c) a polymerization initiator and an aminecompound of formula (I) ##STR3## wherein each of R¹ and R² is,independently, a hydrogen atom or an alkyl group which may contain afunctional group or a substituent, and R³ is a hydrogen atom or a metalatom, wherein, on the basis of the total amount of components (A1) (a),(b) and (c), the amount of component (A1) (a) is 1 to 50% by weight, theamount of component (b) is 1 to 98.99% by weight, and the amount of thecomponent (c) is 0.01 to 50% by weight, and wherein the curablecomposition has a viscosity in the range of from 100 to 30,000 cp whenmeasured at 37.5° C.
 2. A method of treating a tooth surface, whichcomprises applying a primer composition comprising(a') 1 to 30% byweight of at least one member selected from4-(meth)acryloyloxyethyltrimellitic acid or an anhydride thereof andN-(meth)acryloylaminosalicylic acid, (f') 30 to 90% by weight of atleast one member selected from the group consisting of an aqueousethanol or an aqueous acetone, (g') 1 to 20% by weight of a(meth)acrylate having an oxyalkylene group, and (c') 1 to 20% by weightof an aromatic sulfonateto a tooth surface, and then applying a visiblelight-curable composition comprising (a') 1 to 30% by weight of at leastone member selected from 4-(meth)acryloyloxyethyltrimellitic acid or anarthydride thereof and N-(meth)acryloylaminosalicylic acid, (b') 30 to90% by weight of at least one member selected from the group consistingof 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,glycerol (meth)acrylate, erythritol (meth)acrylate andpoly(meth)acrylate of an polyepoxy compound of bisphenol, (c') 0.1 to 5%by weight of a combination of d,l-camphorquinone which is a visiblelight sensitizer and N-phenylglycine, and (d') 3 to 20% by weight of a(meth)acrylate having an oxyalkylene group in its molecule, and having aviscosity in the range of from 100 to 30,000 cP when measured at 37.5°C.
 3. A method of treating a tooth surface, which comprises applying aprimer composition comprising(a') 1 to 30% by weight of at least onemember selected from 4-(meth)acryloyloxyethyltrimellitic acid or ananhydride thereof and N-(meth)acryloylaminosalicylic acid, (f') 30 to90% by weight of at least one member selected from the group consistingof an aqueous ethanol or an aqueous acetone, and (g') 1 to 20% by weightof a (meth)acrylate having an oxyalkylene group,to a tooth surface, andthen applying a room temperature curable composition comprising (a') 1to 30% by weight of at least one member selected from4-(meth)acryloyloxyethyltrimellitic acid or an arthydride thereof andN-(meth)acryloylaminosalicylic acid, (b') 10 to 60% by weight off atleast one member selected from the group consisting of 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycerol (meth)acrylate,erythritol (meth)acrylate and poly(meth)acrylate of an polyepoxycompound of bisphenol, (c') 0.1 to 10% by weight of a combination of atyeast one member selected from d,l-camphorquinone, an organic peroxideand an inorganic peroxide with N-phenylglycine, (d') 10 to 60% by weightof a (meth)acrylate having an oxyalkylene group in its molecule, and(e') a filler containing any one of 10 to 60% by weight of a zirconiumoxide filler having an average particle diameter of 0.05 to 10 μm, 5 to30% by weight of a spherical silica filler having an average particlediameter of 1 to 10 μm and 5 to 30% by weight of an organic compositefiller having an average particle diameter of 1 to 30 μm.
 4. The methodof treating a tooth surface according to claim 1 wherein the primercomposition further comprises (g) a polymerizable monomercopolymerizable with the polymerizable monomer having an acidic group inits molecule (A) (a), or (c) a polymerization initiator, or both (g) and(c).
 5. The method of treating a tooth surface according to claim 1wherein the curable composition further comprises (d) polymerizablemonomer copolymerizable with (A1) (a), (b) or both (A1) (a) and (b),wherein, on the basis of the total amount of (A1) (a), (b), (c) and (d)the amount of (d) is 3 to 50% by weight.
 6. The method of treating atooth surface according to claim 5, wherein the primer compositionfurther comprises at least one of (g) a polymerizable monomercopolymerizable with (A) (a) and (c) a polymerization initiator.
 7. Themethod of claim 1 wherein the curable composition further comprises (e)at least one member selected from the group consisting of organicfiller, inorganic filler and organic composite filler, wherein, on thebasis of the total amount of components (a), (b), (c) and (e), theamount of (e) is 15 to 85% by weight.
 8. The method of claim 7, whereinthe primer composition further comprises at least one of (g) apolymerizable monomer copolymerizable with (A) (a) and (c) apolymerization initiator.
 9. The method of claim 5 wherein the curablecomposition further comprises (e) at least one member selected from thegroup consisting of organic filler, inorganic filler and organiccomposite filler, wherein, on the basis of the total amount ofcomponents (a), (b), (c) and (e), the amount of (e) is 15 to 85% byweight.
 10. The method of claim 9 wherein the primer composition furthercomprises at least one of (g) a polymerizable monomer copolymerizablewith (A) (a) and (c) a polymerization initiator.
 11. The method of claim1 wherein the amine compound of formula (I) is N-phenylglycine orN-tolyglycine.